The non-linear correlation function and the shapes of virialized halos

The correlation function xi(r) of matter in the non-linear regime is assumed to be determined by the density profiles rho(r) and the mass distribution n(M) of virialized halos. The Press--Schechter approach is used to compute n(M), and the stable clustering hypothesis is used to determine the density profiles of these Press--Schechter halos. Thus, the shape and amplitude of xi(r) on small scales is related to the initial power spectrum of density fluctuations. The case of clustering from scale-free initial conditions is treated in detail. If n is the slope of the initial power spectrum of density fluctuations, then stable clustering requires that xi(r)\propto r^{-gamma}, where gamma is a known function of n. If halo--halo correlations can be neglected, then rho(r)\propto r^{-epsilon}, where epsilon = (gamma+3)/2 = 3(4+n)/(5+n). For all values of n of current interest, this slope is steeper than the value 3(3+n)/(4+n) that was obtained by Hoffman & Shaham in their treatment of the shapes of the outer regions of collapsed halos. Our main result is a prediction for the amplitude of the non-linear correlation function. The predicted amplitude and its dependence on n are in good quantitative agreement with N-body simulations of self-similar clustering. If stable clustering is a good approximation only inside the half-mass radii of Press--Schechter halos, then the density contrast required for the onset of stable clustering can be estimated. This density contrast is in the range ~300-600 and increases with the initial slope n, in agreement with estimates from N-body simulations.Comment: 8 pages, uuencoded, gzipped, postscript, submitted to M

Validated pre-discharge survey of patient satisfaction in orthopaedic care

Background: Worldwide, increasing concern has been given to the assessment of patient satisfaction survey as a method of monitor of the quality of health care provision in the health institutions. The study aimed to assess the level of patient satisfaction with preoperative and postoperative surgical services and its associated factors. Study includes Experience of 17 questionnaires.Methods: A total of 507 indoor patients were taken on a random basis full filing the inclusion and exclusion criteria, over a period of 1 year from December 2017 to January 2018. Firstly, we applied Cronbach's alpha to know the reliability of survey questionnaire, then we collected the final data. Association between two non-parametric variables was seen using Pearson’s chi-square test. A p value of less than 0.05 was taken as statistically significant. Data was analysed using SPSS 21.0.Results: Patients with good satisfaction rates were 60.2%. We found that males are more satisfied then females with Pearson Chi-square value=8.033, df=1, p value=0.005. Patients with age of above 80 years and between age group of 21-40 years have comparatively lower satisfaction rates with Pearson Chi-square value=33.265, df=4, P value=0.000.Conclusions: Assessing patients’ satisfaction rates can be a simple and cost effective technique for evaluating the services provided by health care providers and institutions and should be conducted periodically to detect carelessness and bring about overall improvement in the quality of care provided. This should be generalised and universally accepted.

Optimisation of a Brownian dynamics algorithm for semidilute polymer solutions

Simulating the static and dynamic properties of semidilute polymer solutions with Brownian dynamics (BD) requires the computation of a large system of polymer chains coupled to one another through excluded-volume and hydrodynamic interactions. In the presence of periodic boundary conditions, long-ranged hydrodynamic interactions are frequently summed with the Ewald summation technique. By performing detailed simulations that shed light on the influence of several tuning parameters involved both in the Ewald summation method, and in the efficient treatment of Brownian forces, we develop a BD algorithm in which the computational cost scales as O(N^{1.8}), where N is the number of monomers in the simulation box. We show that Beenakker's original implementation of the Ewald sum, which is only valid for systems without bead overlap, can be modified so that \theta-solutions can be simulated by switching off excluded-volume interactions. A comparison of the predictions of the radius of gyration, the end-to-end vector, and the self-diffusion coefficient by BD, at a range of concentrations, with the hybrid Lattice Boltzmann/Molecular Dynamics (LB/MD) method shows excellent agreement between the two methods. In contrast to the situation for dilute solutions, the LB/MD method is shown to be significantly more computationally efficient than the current implementation of BD for simulating semidilute solutions. We argue however that further optimisations should be possible.Comment: 17 pages, 8 figures, revised version to appear in Physical Review E (2012

Radiographic evaluation of knee joint space width using fixed flexion view in knees of Indian adults

Background: The objective of this study is to evaluate the tibiofemoral joint space width in the medial and lateral compartments of the knee using digital radiograph. The measurement of knee joint space width (JSW), in between the femur and the tibia is a way of evaluating the tibio-femoral cartilage thickness. This study is aimed at establishing normal references of joint space width for use in diagnosis and follows up of knee cartilage diseases.Methods: This study is prospective and carried on 50 subjects at SAMC & PGI, Indore, M.P. One patient refused to sign the consent and was excluded. All subjects were healthy adults with sedentary lifestyle. All subjects underwent x-ray of bilateral knee joints. The joint space width of both medial and lateral compartments of each knee was measured using the scale in the computerized software.Results: The average age in the study group was 44.59 years with male preponderance.The mean left medial and lateral joint space width was 5.34 mm±1.26 mm and 5.21 mm±1.04 mm and on right side was 5.26±1.11 mm and 5.57±1.57 mm, respectively. No statistically significant difference was found between right and left knee joint space width compartments.Conclusions: The values obtained after observing the radiographic references showed no significant gender variation in knee joint space width. But, it is seen that there is a decrease in joint space width with increasing age, which progresses towards osteoarthritis of knee